


precommitment

by gisho



Series: wherin Gil and Tarvek work some things out [1]
Category: Girl Genius
Genre: Game Theory, Gratuitous Worldbuilding, Warning: serious and positive discussion of mind control, consensual drug use, consequentalist ethics, very talky
Language: English
Status: Completed
Published: 2018-01-09
Updated: 2018-01-20
Packaged: 2019-03-02 15:47:56
Rating: Not Rated
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 2
Words: 8,234
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/13321416
Author URL: https://archiveofourown.org/users/gisho/pseuds/gisho
Summary: Wherin Tarvek proposes an experiment, Agatha has questions, and Gil has ethical concerns.(edit: now with not-originally-planned second chapter)





	1. Chapter 1

\---

He'd expected Agatha to be horrified at the idea; she was sentimental. He'd expected Gilgamesh to find it more compelling, but throw up a list of objections in his usual self-sabotaging scrupulous way. _Practical_ wouldn't have been his guess for the first one, but it was easy enough to break down.

"I can _make_ another Spark Wasp," he says, "or at least the relevant chemicals from one. We have Maaganox's notes and enough information on Snarlatz's process -" They're still staring at Tarvek with expressions of overblown dismay. He sighs. "It's not as difficult as it looks. Few things are, once you know they're possible."

There was a time when Gilgamesh would have lept on Tarvek and tried to strangle him for that remark. He hasn't really _mellowed_ , but he's learned to be a little more patient. And the sheer surprise has robbed him of momentum, which is why Tarvek dropped the idea in the middle of a more-or-less innocent conversation about diplomacy with Paris. 

"Just because it's _possible_ doesn't mean it's a _good idea_ ," Agatha says, eyes narrowed in the way that means she's debating whether to go straight to hitting things. Her toes are curled into the sofa cushion, just shy of Gil's thigh, and her skirt is bunched up over her knees. Tarvek can't help but watch her, as inevitable as heliotropism. 

Gilgamesh is still too busy being disturbed to be properly angry. "Obviously not," he manages. "You'd have to destroy your notes, that's the kind of - Why are we even _thinking_ about this?" He half-winces, like someone flinching away from a blow in slow motion. His hair is more of a mess than usual, from Tarvek ruffling it before he sat down beside the hearth, and it makes him look young. 

Tarvek interjects, "Because I suggested it?"

"You - " Gilgamesh's face twists into annoyance. Tarvek wonders for a second if he could just _pester_ the man into agreeing. "You must be mad. No rational person would _volunteer_ for a wasping."

\--

Three years ago Gil would have been giving Tarvek a good shaking by now, but he's gotten too used to being the reasonable one. Besides, it's hard to muster anything but bafflement as Tarvek goes on, as casually as if he _weren't_ talking about _the Other's mind-control_ , "It's perfectly rational. It would be a strategic advantage, even."

"How exactly?" Agatha looks - less horrified than she did seven sentences ago, but she must be curious, and now Gil is too. 

Tarvek blinks at them. "I want you to trust me, and right now you're both still convinced I have my own agenda."

"Don't you?" Gil can't keep from rolling his eyes. 

"Well. Yes. But not anything that could hurt Agatha, and we're never going to be able to _work_ together if you're always waiting for me to stab you in the back." He pushes his glasses up his nose. "If it's literally impossible for me to betray you, you can stop worrying and I can stop trying to prove that I won't over and over. Like I said. Advantage."

"The problem with that strategy," Agatha offers, staring into space, "is that we don't know enough about that variation of the wasp to be absolutely sure it would work. The advantage disappears if there's a way for you to work around it." She frowns at nothing, scratching at her cheek the way she always does when she's thinking hard. "Although if we started by getting more data ..."

Tarvek is fiddling with his glasses as if he shouldn't be running away screaming by now. "You know it would prevent any _overt_ moves. And you'd get better data observing its effects directly. Advantages all around."

There's still something horrified clawing at Gil's subconscious, but he pushes it back for the moment, because there are scientific implications here and he wants to explore them before he lets himself think about how _completely terrible_ actually _doing_ \- alright. So much for examining things logically. He decides to settle for sitting quietly and listening.

\--

There are gears spinning in Agatha's head, but not the usual assortment. She does mechanisms. Looked at the right way everything is a mechanism; it's only that with human psychology, the effort of turning her mind to see it is more than the effort of, for example, turning to Tarvek and asking, "Do you know if the Spark Wasp works normally on someone in full-blown fugue?" 

"I don't." He shrugs apologetically. "Fugue does all sorts of things to someone's mind -"

"- and the Spark Wasp was never tested properly. Right." Agatha drums her fingers on the sofa arm, trying to shake her half-formed ideas into shape. "So, we don't have any idea how much someone's mental state affects their ability to resist commands."

"It wasn't _meant_ to affect it at all."

"Nothing was, right. Do you know of anything that does?"

"For the standard version, the only major difference was whether it was one of the geisterdamen giving orders or, well, you." Tarvek has given up on cleaning his glasses; he's spinning them idly between his fingers. "Anevka was convinced that people imprinted on whatever voice gave them commands initially. For the Spark Wasp, it was never tested properly." 

"Of course. Wasn't it enough that the Knights of Jove were doing horrifying mind-control experiments? Did they really have to ignore scientific procedure too?" Agatha scowls at nothing in particular. "What _do_ we know?"

"The same things we know about the standard version." Tarvek starts to tick them off with his other hand as he talks. "There's a built-in compulsion to keep it secret; that starts working as soon as someone's infected. Commands can override a reflex, like flinching away from a hot surface, but we don't know what they do to autonomic reflexes, and we really should find that out. But the conscious mind is obviously involved in interpreting orders - they go through the superior temporal gyrus. We know that being deaf from birth keeps someone from even receiving the initial keep-secret order. So does not understanding any major Europan language."

Agatha blinks. It makes a twisted sort of sense, but - " _How_ do you know that?"

"One of the original hives landed in the Basque Country. Twenty years ago," he points out, with an apologetic glance at Gil. "It infected an isolated mountain village, but most of the people there only _spoke_ Basque - when they all felt normal the next day, they assumed the hive was a dud and went about their lives. It became a part of village lore. It would have revealed the existence of secret revenants long before the Vespiary Squad worked it out, except that the only villagers who travelled further than the next town were the ones who spoke Castilian. There were local rumours, but we didn't pick those up for a decade."

Gil's hands are clenched into white-knuckled fists, and his face looks like he's fighting back nausea. "You keep using the past tense," he says. "What happened to them later?"

"Nothing!" Tarvek snaps back. "As far as I know they're not even on the Vespiary Squad checklists! It's not like the Basques were going to rise up in revolt! Why do you always assume the worst?"

"Because with your family it's generally _true_!"

Here they are getting into another one of their stupid arguments, and they're flat-out ignoring the obvious, interesting question. Agatha crosses her arms as she stands; she needs to find a notebook, this is _important_. "What about the people who _learned Castilian later_? Did the silence command _take effect then_ , or was it a _one-time effect_?"

Tarvek blinks, and his hands go still. "I ... have no idea."

"We should _find that village_ and _check! Do you speak Castilian?_ "

"It would take days to get there," Tarvek points out, in his calm, placid talking-someone-down voice. "It would make more sense to test it here by giving someone a command in code and then giving them the code key." 

" _Right._ " Agatha finally finds her pencil under the stack of maps. She can think of so many things they could _find out_ , and not just about _wasps_ , they might manage a _generalized_ method of protection against any mind control that _needed_ the _superior temporal gyrus_ , which was _most of them_. "Let's _find the reagents, we should start right away! Where's the best chemistry lab?_ "

A hand descends on her shoulder, big and steady and _distracting_. Gil says, voice crackling with the edge of a fugue himself, " _We're not doing this._ "

" _Why not?_ "

Gil sighs heavily, and looks back at Tarvek, who's put his glasses back on and is holding his hands in front of the fire where the thermal radiation must be the most intense. "Tarvek. Stick your hands in the fire."

"What? Why would I do that?" Tarvek doesn't sound indignant so much as confused.

" _Exactly!_ " Gil throws his hands in the  
air in theatrical frustration. 

Agatha scowls, incipient fugue dashed aside and leaving her twitching. "Gil. Unpack."

"We know that the standard wasps make people obey even when the orders aren't very precise. Or aren't meant to be orders! Remember Rovainen? I don't want you to hurt Tarvek by _accident_ just because he's an idiot and takes something you said the wrong way."

Oh. _Oh._ The thought yanks her back to reality in an instant, making her flinch at how ready she'd been to try it. 

But apparently it doesn't bother Tarvek, because he keeps scowling at Gil. "You don't think she knows how to be careful? For the sake of understanding how to modify -"

"Something we should never be getting within a day's flight of? Shards and ash, I thought we'd gotten the idea through your skull that wasping shouldn't happen to _anyone_!"

"Not even, say, Othar Trygvassen?"

"He may be -"

"- a serial murderer?" Tarvek smoothly interrupts, and spreads his hands in a casual can't-help-some-people gesture. Agatha isn't sure if she should interrupt them before they start hitting each other, or let events take their course. The worst of it is, she can see Tarvek's point. Tarvek goes on, "Would you rather get wasped or hung? Because for _some_ people those are the choices we have to keep them from doing any more damage!" The calm doesn't make it to the end of his sentence. 

Gil's answer is almost a scream, but at least there aren't harmonics in it. "Those aren't the only choices! That's - why do you always jump to the most pessimistic interpretation of everything?" There's something raw and dangerous in his voice, and Agatha is suddenly reminded of the two-and-a-half years he spent trying to hold the Empire together and grinding himself to pieces with the effort. "Besides, would it really be fair to make innocent people share a city with, oh, Eric Loder even if he had unbreakable orders never to touch electroplating equipment?"

"Who's Eric Loder?" Agatha interjects.

Gratifyingly, they both turn their faces to her right away, argument set aside. It's Tarvek who answers, looking thoughtful. "These days? A sculpture outside the Palais de Justice. _The Regretful Criminal_ , I think Voltaire titled it."

"Poetic justice," Gil adds brightly. 

"He was no great loss." Tarvek sighs. "But some criminals could do a lot of good as tame monsters, and some - " He breaks off, fiddling with his glasses again. "There was a man who worked at the Balan airdocks. A stevedore. He had a temper, the neighbors said later he had a temper. One night he had an argument with his boyfriend over dinner, and then his boyfriend had a smashed skull and the Watch had the world's easiest murder investigation ... We didn't hang him, he did that himself in jail the next night. Maybe one stevedore more or less is no great loss to the world, but it would have been nice to kill the temper and salvage the man."

\--

Now _he's_ being stupidly sentimental, thinking about ideals of justice, instead of the real world where the appearance of justice, public opinion, expediency, are more important than a few lives. But this wasn't the argument Tarvek expected to have. Maybe in a few years, when they knew _how_ to make such a delicate adjustment to someone's mind, he would have raised the idea. When - with any luck - their corner of the world was peaceful enough that popular opinion was in favor of mercy.

Agatha is leaning against the table, hands tight on its edge, and Gilgamesh has settled back onto the sofa with the air of a man composing a counterargument. Tarvek decides to head him off. "I grant we couldn't use anything that even _resembles_ the wasps for that," he says. "Even ignoring the specificity issues, there would be riots if it became public knowledge."

"Yes," Agatha says. She hasn't let go of the table. "Some people would rather be hung than wasped."

But some people would rather be wasped than hung, and even if they've done something awful maybe they should get the _choice_ , and - this isn't an argument he wants to have right now. Tarvek takes a few careful, shallow breaths. 

Agatha goes on, "And anyway, the specificity issues are too big to ignore. We'd want to detune the wasps just to eliminate the chance of Geisterdamen giving people orders, and that means putting _all_ the orders in the initial chemical encoding, and that means working out _exactly_ what they have to say. I wouldn't want to order someone not to hurt any person and then find out they stabbed a construct because they really don't think constructs are people, or set fire to a house without checking if it was empty, or just decided to do as much property damage as they possibly could out of spite."

"You'd have to experiment," Gilgamesh says, and there's something dark and dangerous in the back of his eyes. "And we have a willing test subject right here."

There's just enough contempt in his voice that Tarvek's temper flares up and overrides his self-preservation instincts, which is a reaction he'd have to get rid if Gilgamesh weren't the only one who regularly had that effect on him. "Are you implying I _shouldn't_ trust Agatha?"

"I'm saying you shouldn't ask that _much_ from her! Having to think about every word she says to you for the rest of our lives?"

He's tempted to tell Gil to turn down the drama dial, but it would be hypocritical. Tarvek settles for, "We know how to cure wasping, if you've forgotten. A week or two would be long enough to test the limits of the command voice." 

With the air of a small child being righteously stubborn, Gilgamesh folds his arms. "I thought the point was for us to trust you? If we cure you a week later, how do we know you're not going right back to being a slimy weasel?"

Tarvek considers Agatha. Her scowl is gone, at least, and she's spinning her pencil between her fingers, the restless, casual motion of someone distracting herself from a scientific problem. The look on her face is somewhere between annoyance and pity. It's not a good look for her, and it makes Tarvek want to apologize for putting it there. He feels wretched. 

Mostly, though, what he feels is tired. 

"You ask," he says, and doesn't meet either of their eyes. "You ask me for the truth, and I have to give it to you. That's how it works."

\--

Agatha narrows her eyes. Tarvek looks downright wounded, perched on the hearth but turned away from the fire like he doesn't deserve the warmth; the kind thing to do would be to pull him onto the couch and leaven the complaints with kisses. But she wants him where she can see his face.

"Gil's right," she says, trying not to sound _too_ angry. "We'll never use any variation of the Other's mind control, so there's no reason to experiment with modifications."

"Alright." Tarvek is still staring at the floor.

"At least you can see sense," Gil adds, glaring at nothing in particular. 

"But," Agatha goes on, "Tarvek has a point about telling the truth -" 

As she'd expected Gil bursts out with a protest before she can finish her sentence. "That's not enough of a reason to make another Spark Wasp! Agatha, you can't possibly -"

"I'm not," she snaps, and Gil breaks off. At least he knows enough not to talk over her. Agatha takes a deep breath and continues, eyes narrowed. "Tarvek. Remember the day we met, when your father invited me to dinner?"

He understands right away. She can tell by the way Tarvek's face goes red, and he lifts his hands as if he could hide behind them. "Do you want that formula?"

"It would be a start."

It's Gil's turn to tap his fingers and say, "Unpack?"

Oh. Right. Tarvek looks too mortified to say anything, so Agatha takes pity on him. "He put a truth serum in my wine," she explains. "I spent the whole dinner babbling about my secrets. Finding out I was a Heterodyne, fleeing from the Baron, _everything_. It all felt perfectly natural."

Through his fingers Tarvek mutters, "And you thought Gilgamesh needed a bigger death ray. You went on about him for most of the dessert course."

If he's trying to embarass her with that remark, he's failing. It's Gil who promptly starts blushing, instead, and hisses, "I thought there were better ways of dealing with trouble."

"Most of the time there are," Agatha assures him. Sometime in the years she missed, he'd started going for the swift, certain ways of dealing with rampaging madboys, mundane bandits and axe-murderers, the myriad endless threats to the peace, but she doesn't think Gil ever quite got _used_ to it. She hopes not, anyway; she's the Heterodyne, and that puts her in a _much_ better position to play Stick to his Carrot. Where Tarvek's brand of mercy fits in, they can think about later.

"Most," Gil mutters, and runs a hand through his hair. It doesn't help. "Are we really going to deal with _this_ troublemaker with his own truth serum?"

"I don't see why not." Agatha grabs a notebook that shouldn't have anything in it but clank sketches, and takes three steps back to the sofa.

"How do we know he doesn't have an antidote?"

Tarvek drops his hands and looks daggers at Gil. "You can come up with your _own_ truth serum if you're convinced I'm _that_ sodding much of a weasel."

He must be incredibly off balance if he's swearing. Agatha would giggle at his furious blush, except for the twist in her stomach at the memory of what he offered as if it were the obvious thing to do, and how close she came to agreeing. They still have so much to learn about - 

"Tell me the name of that Basque village," Agatha demands, and spins her pencil ready.

Gil blinks. "You can't be planning to go there -"

"No," she assures him, "but I want the Vespiary Squad to ask some nosy questions when they do. And I can run experiments here on Fraulein Snaug to figure out the limits of the standard wasps. Lucky she hasn't gotten to the cure yet." Snaug, Agatha thinks, is the most likely subject to be brave enough to volunteer. She not only minioned for the man who tried to turn Chääsheim into a giant labyrinth complete with minotaurs, she volunteered to follow him into Castle Heterodyne.

And absurd a thought though it should be about the man who tried to turn Chääsheim into a giant labyrinth, Mittelmind can watch to make sure Agatha doesn't go overboard.

\--

The next good opportunity Gil gets to talk to Tarvek alone isn't until two days later, waiting outside Agatha's lab as she hooks up Snaug to an alarming array of monitoring equipment. Gil still isn't sure he's comfortable with this, but Snaug seems to be. Gil is telling himself as hard as he can that Snaug's opinion is the only one that matters here. 

Tarvek is staring at the opposite wall with the brooding expression that's become his default, since things stopped exploding. It's downright irksome. Gil cuffs him on the shoulder in an attempt to knock it off his face. "Wish it were you in there?" he asks brightly. Might as well start big. 

And of course, Tarvek looks at him like he's trying to set Gil on fire by telekinesis. "Don't be absurd," he hisses. "Agatha said no, that's the end of it."

"Yes, you were counting on that, weren't you?" Gil crosses his arms and meets the glare head-on. No point dancing around. "You had to have known she'd turn you down. Are you seriously still scrabbling around for ways to make yourself look good to us?" 

Tarvek doesn't look away either; he leans close, and his voice goes low, as if he were trying to make sure they weren't overheard. "Why don't you ask once you've mixed up some truth serum I don't have the antidote to?" Gil takes a deep breath, trying to muster an objection, but before he can Tarvek goes on, "I am. I'll keep scrabbling until you stop expecting me to turn on you. Look at it this way, if I did suggest it as a cunning scheme to make Agatha remember the time my father drugged her at a family dinner, doesn't volunteering for _that_ prove my sincerity as - " 

He has to stop then, because Gil has grabbed his neck and tugged him in for a kiss. It seems the most effective way to keep either of them from saying something they'll regret later. 

When they break apart Tarvek is blushing. Gil isn't sure if he wants to shake him for that or kiss him again. He settles for, "I still think you're a weasel." 

"Yes." 

"But you're _our_ weasel. What do we have to do to prove that to you?" 

"Keep screaming," Tarvek tells him, and suddenly smiles. The expression doesn't quite look at home on his face, so it might even be real. "That's how I know you're telling the truth." 

\---


	2. Chapter 2

**Notes for the Chapter:**

> Alright, I decided I needed to add a second chapter to make some things clear. And it turned out longer than the first. Additional warning: consensual drug use.

\--

The glass isn't quite half full. Tarvek takes a long swig before he can start thinking in metaphors. 

"How long before it takes effect?" Gilgamesh asks. 

From the look on his face Tarvek is a little surprised there's no Spark in his voice, especially since that's an absurd question. "How can you trust my answers," he says, "if you havn't checked that for yourself?"

"Same way I know you aren't using an antidote. Like you said. Advantages for all of us." 

That's really amazingly trusting of him under the circumstances. "A minute or two," Tarvek says, and tries to estimate by eye how much he drank, which is tricky, since the glass isn't a cylinder but an actual wineglass of the briefly fashionable Jardin style, mottled with veiny irregularities to resemble something grown. About fifty milliliters? "It might take longer, I'm good at throwing off drugs. The last time I took this I was only weighed thirty-five kilograms, and it was in alcohol which throws off the metabolic reactions. Terrible idea in retrospect. At least I had the sense to be alone in my room, but there are safer ways to force a good mood." 

Agatha takes hold of his wrist. "I don't think it's going to take longer."

Maybe not. Either that was more than fifty milliliters, or the sugar is throwing off his dilution estimate. 

Gilgamesh throws himself down in the other end of the sofa, contriving to land with an arm over Tarvek's shoulders. He would protest, but the weight is comforting. "Not even thirty seconds," Gil tells him. "Strong stuff. Did you design it yourself?"

"Oh no, it's an old family recipe," Tarvek says. "My great-aunt Rappacini came up with it. Have you heard of her?" he adds, because Agatha's face is crumpling into a scowl.

"Yes." Agatha's hand tightens on his wrist. "Your obnoxious cousin Martellus threatened me with one of her concoctions once. He said it would have made me his adoring slave."

It suddenly seems very important to reassure Agatha, and Tarvek tells her, "Only if he adjusted the formula. She tried that one on my great-uncle and he still shoved her off a parapet." The serum must be taking effect, he thinks, for him to have tried to comfort her without actually _considering_ the words. From her look of horror it didn't work, so he decides to try again. What comes out this time is, "Tweedle's too smart to want his enemies stupid."

"Let's not worry about Tweedle," Agatha says, gentle and reassuring, and pats his hand. It feels nice. He really should be panicking by now, but he can't bring himself to care. 

\--

Agatha remembers feeling like the world was a nice place and nothing in particular could go wrong, and smiling like a lunatic as she babbled. Most of the tension has melted away from Tarvek's face, but he's still managing to look upset, as if he should feel bad for bringing up his awful relatives. Well, they _asked_. 

She'll just have to be careful what else she asks about.

"Well, obviously not now," Tarvek says. "I used to worry about Tweedle all the time. He wasn't smarter than _me_ , but he was smart enough to work out who else was in his way. That hunting accident was just _tasteless_ , though. Just because Xantippus was a blowhard doesn't mean he was careless." 

Gil puts in, "You've never done anything like that, have you?"

"Of course not! There wouldn't have been any point." Tarvek nods eagerly, as if that settles the argument.

She was starting to feel bad for taking him up on the offer, but Agatha finds herself wincing at how casually Tarvek said that, as if he _would_ have arranged fatal hunting accidents for his relatives if he'd only had a good reason. What would have counted as a good reason, though, if securing the Lightning Crown for himself didn't qualify? Was it only that Martellus had taken out all the strong claimants first? Maybe she's being too cynical. Anyway, it's not as if Agatha would stop loving Tarvek if he had killed off a few difficult relatives. She knows from experience how blurry the edge of 'self-defense' can get. 

Or 'defense of others'. It was Anevka who set Prince Aaronev aflame, while Tarvek was still trying to argue him out of overwriting Agatha's brain. _Bloodthirstiness_ has never been Tarvek's flaw.

Gil's hands are clenched, but he keeps his voice gentle as he asks, "Are you planning to?"

"No. Agatha wouldn't like it. Besides, that sort of thing shouldn't happen." Tarvek scowls. "Enough people die horribly already. It's much more elegant to find a way to use them. I admired your father for that, you know," he adds to Gil, almost sounding wistful. "He was so good at finding the right monster for the job. And vice versa. Dupree is a terrible excuse for a human being and calling her a shark would be an insult to sharks, I mean, sharks are just hungry, but she's a brilliant battle commander. The tactical instincts on that woman - they'll write books about her someday. It's just amazing the Baron gave her the chance. I hope you'll keep giving me a chance," he adds, and the worried look is back.

Gil tugs him closer. "You're too useful to get rid of."

"We love you," Agatha adds, because it's true, and if Tarvek can't reassure himself with utility calculations, they probably can't either.

"But you see, that's exactly what you would say if you were planning to steal all my notes and then kill me. Or just lock me in a lab somewhere so I could mix potions for you. Not that I'd mind that much. Did I just say that aloud?" Tarvek grabs the wineglass and takes another gulp. "Of course I did, it's a truth serum," he says to its surface. 

Agatha has a sudden mad urge to laugh.

Gil plucks the glass out of Tarvek's fingers. "If you were expecting us to do _that_ why exactly did you volunteer to let us use mind-control on you?"

The look on Tarvek's face is mostly baffled, eyes wide and brow furrowed, but there's something miserable around the edges. "I wasn't expecting you to. You're not that kind of people. But I am, so I had to find a better reason for you to trust me. It's just basic strategy," he adds, sounding relaxed now he's in his element. "Anyone can _say_ anything. If you want someone to believe your promises there has to be some good reason you can't break them as soon as they're inconvenient. I could tell you to just have the Castle drop me in a bottomless pit if I betrayed you, but that only works if I never leave Mechanicsburg."

A voice from the ceiling murmurs, "Capital idea. I could have the seraglio ready in no time at all."

Agatha stands up, to make it more obvious she's giving the ceiling a dirty look. " _Castle!_ What did I say about interrupting us?"

"Oh, but if there's -"

"Did I ask?" Agatha thinks for a second, then pulls her screwdriver out of the hidden pocket over her hip, and heads for the corner where there's a piece of wooden panel over the stone for no immediately obvious reason. She knows how these things work by now. "Consider this a promise," she snaps, and pulls it away. Just as she expected, there's a control conduit, and that green tube is the visual line. "I will put you back later, because otherwise you'll sulk." She yanks on the visual line, and it comes loose in her hand with a tiny flash and a crackle. 

It still takes a few awkward seconds before the Castle mutters, "Sorry, Mistress."

"Prove it by shutting up."

"Yes, Mistress."

Tarvek is leaning over the back of the sofa, watching her with bright, adoring eyes. "You're so good at that," he tells her. "I love the way you just take over everything with sheer force of personality. It's beautiful. I know Sparks are supposed to be like that, but most of the time it only works on a few minions, you can make it work on _other Sparks_. You make it work on _Gilgamesh._ "

"That's because I'm in love with her," Gil admits. For some reason he's gone bright red.

Tarvek nods eagerly. "That's how it works! How long did it take? It was about a day for me," he adds. "At least I noticed it right away. I don't really know how long it took me to fall in love with you. Weeks, probably."

"Wait, what?" Gil sounds so honestly baffled by this tangent Agatha wants to burst out giggling. She takes Tarvek's hand.

Tarvek doesn't seem to notice. He goes on, sounding quite cheerful about it, "I didn't know what it was, back then. I'd never been in love before. "It just felt good to be near you." He nods again, point made. "And obviously the Baron was hiding something about you, it made sense to look into, but it didn't make sense to keep looking for four years. That was how I knew I was in love."

The glass of truth serum is still clutched in Gil's other hand. He glares at it as if it's personally responsible for this, which is true enough. "What changed your mind?"

"Nothing." Tarvek blinks. "I'm still in love with you. Isn't it obvious?"

Well, it was obvious to Agatha, but she has the advantage of outside view. Apparently it's a complete revelation to Gil. He stares at Tarvek in shock for several seconds before he manages, "Not really."

"Well, I wasn't going to admit it while you were acting like a brazen lothario in Paris. But it must be obvious _now_. I love you and I want you safe and I want to work with you. Otherwise I would have done a lot more to subvert your general staff. Doctor Chouteh still thinks your father has his claws in you, and Marshal Fern doesn't care who she's working for as long as they keep the roads repaired, and they both _trust me_. I admit getting you deposed would upset Agatha, but if I made the reasoning plausible she'd accept it. And talking about this is probably making you _more_ paranoid," he adds, "but will you at least believe me when I say I wouldn't do anything to get rid of you?"

Gil is too busy blinking to answer. Agatha tightens her fingers on Tarvek's and says, "I know you wouldn't. We've been through too much together."

"That doesn't always help. I still betrayed Anevka." The euphoric haze must be blunting the edge of a painful memory, because he just looks a little annoyed at the thought. 

What is she supposed to say to that? There are all sorts of reasons not to trust Tarvek, and Agatha decided to ignore them all in favor of the instinct that said he was worth keeping. If Tarvek is a little more consistent, if he just can't ignore that they should, logically, not trust him outside of their sight - 

No wonder he _asked_ them to use the Spark Wasp on him. There's a horrible logic to it. 

She's still mulling it over when Gil stops fiddling with the wineglass and drains it.

\--

It tastes almost stickily sweet, which Gil knows is because they added sugar to make it drinkable despite all the amytalone. Whether it will work on him - well, they'll know in about forty seconds.

"Oh," Tarvek says, in a voice like someone who's just had an important revelation. "That works."

Agatha grabs the glass away and sets it down out of reach, which seems pointless since he took all the rest of it. It's not like the drug will affect his hand-eye coordination. "We're not done asking _Tarvek_ questions," she snaps. "You could have done that later."

"I didn't want to lose my nerve," Gil admits. It doesn't feel dragged out, the serum hasn't taken effect yet, which must mean the soft sense of relief is entirely natural.

Agatha shakes her head, but she settles back onto the sofa, on Tarvek's other side. She hasn't let go of his hand. Tarvek just looks at Gil, and the soft, adoring look is one he can't remember seeing for - fourteen years? Ever? It's not familiar, but it's good to see. Tarvek says, "I didn't volunteer for this because I don't trust _you_."

"Tell me why, then," Gil says. 

"Exactly what I said. I want you to trust me." Tarvek grabs at Gil's shoulder, face painfully earnest. "It's not enough to love someone," he says, with urgency in his words, as if it were a secret. "And we _have_ to work together, it's not just about us, it's for the sake of the peace. So even if you wasped me and never gave me the cure, it would be better than us working at cross-purposes. But I really didn't think it would come to that. You're both too good to use mind control any more than you have to."

"See, that's where it went wrong," Gil tells him. It's been twenty-seven seconds, and he can feel his annoyance melting away. It's a strange sensation. The effect time is more like he'd expect for an injection, but these things get fuzzy with Sparkwork. "Thinking we'd use it at _all_ just makes us wonder what you're plotting that we would be tempted. Makes me wonder," he corrects himself, because Agatha seems to have a massive blind spot about Tarvek. Just because he's on their side doesn't mean he doesn't have his own agenda. He _admitted_ to that much. Gil isn't angry about it, because right now everything is fine, but he's curious. "What are you plotting, anyway?"

"Oh, lots of things." Tarvek waves a hand in a vague circle, as if he were trying to gesture at the whole of Europa. "I have to consolidate my hold on Tweedle's followers, to start, and about half of them still have a grudge against Baron Wulfenbach, so I'll have to slander the Wulfenbachs and imply I'm biding my time until I can stab you in the back, at least until they renew their oaths of fealty. Sorry." He gives Gil a half-smile. "The Pope of Avignon just wants a bishop back in Red Cathedral - alive - so I need to talk Agatha into picking a nice tractable bishop, and the Pope of the Tsars wants us to send the Jägers to annoy Pavel Pavlovich, so I need to stall him for a year while Pavlovich gets his copper mines going, and the Pope of Dublin wants a little more reasonable deal with the Corbettites. They're worth it, you know. Europa hasn't been so connected since the Romans. The cities, at least. Which is another thing." He points dramatically at nothing in particular. "I know your father liked airship commerce, but if we're going to drag Europa kicking an.d screaming into the twentieth century we need good roads to do it on."

Gil can't help but point out, "It won't be the twentieth century for five years."

"That means we can build up steam! Every little obscure village. There's supposed to be a Spark in Warsaw who makes self-assembling brick houses. We need to kidnap him and make him do it with flagstones. Or work out the lost secrets of permaconcrete. There's supposed to be a recipe in the old Vatican library. Maybe if we offer a bounty we can get someone as stupidly reckless a glory-hog as you to fetch it."

"It would take significantly _more_ reckless a glory-hog than _me_ to go into the Vatican library. I like my bones the shape they are." Gil is distantly aware that he's starting to babble, but it seems the right thing to do. Not that there could possibly be a wrong thing. "It's not like getting into the Blue Caverns. I heard about a team from the Milanese Academy that tried it two years ago, and only two of them came back, and they both had bright green legs and refused to tell anyone why. That was a team with antacid suits and serinusoids, I don't know what a lone adventurer would make of it. It would be amazing if someone cracked the place, though," he finds himself saying. "We don't even know what we don't know about Roman technology."

"Well, _somebody_ knew how to make water flow uphill. Simple enough with a gravitometric inferotron, but they did it with _rocks._ " Tarvek sighs in wistful admiration of whatever long-vanished Spark was responsible for the Roman fountains. 

This is all so pleasant to ramble about, Gil could spend hours thinking about lost arts and how to un-lose them, but Agatha interrupts, "Tarvek, do you have any devious plans that aren't just about playing politics and building things? Anything that would reduce Gil's influence?"

Apparently Tarvek is doing his best to beam at them both simultaneously, but with one of them on either side the average lands somewhere near the fireplace. "Of course not," he tells them. "It's important to consolidate power, but if we can consolidate on all three of us, that works just as well. Maybe better. I don't want to do this alone." He sighs, and wilts toward Gil like a pneumatic stand with a leak. "We can play carrot-and-stick and spread the workload, those are the logical reasons, and why would I get rid of someone with experience running an empire? But I could rule Europa alone. If I had to. I'm the Storm King, it's my duty. I'd just - it would be so much better to have you both there. You _understand_." 

That's good to hear, and not just because everything feels so nice right now. 

Tarvek seems to have said everything he wanted to, and he's settled comfortably against Gil's shoulder, with the air of someone who doesn't intend to move for a while. Gil wraps his arm around Tarvek again. There was something he wanted to say, something important, but it's hard to think without something to worry about. What would have made him suspicious, if he weren't too contented to think about what Tarvek might be plotting? It's hard to model his _own_ suspicious, analytical mind in this state, let alone - oh. Right. Gil announces, "It's a feedback loop. You know it's a feedback loop, right?"

\--

"Unpack?" Tarvek says, blinking. "Sorry. This stuff makes it hard to focus."

That much is obvious, from the way they've been drifting around the questions that were their whole reason for doing this. Agatha hadn't expected to be the only sober one in the room. Unless you count the room itself, but knocking out its visual perception is enough to make the Castle leave them alone. 

It takes Gil a few seconds to answer; from his pinched look of concentration he's trying to string the words into a sentence with no tangents. "Trust. I would have forgiven you dealing with Lucrezia, except you'd gotten up to so much in Paris - they still havn't rebuilt that cabaret, you know. Nobody can get into the basement to check the cadmium levels." 

Trying and failing. "Feedback," Agatha prompts.

"Right. So I was already suspicious, and so everything you do that _might_ be part of some scheme looks worse. Confirmation bias. It's not completely rational. And maybe it would go away if we just worked together long enough, but you keep saying things that make me worry again. You told us to use mind control on someone to keep them from working against us! It doesn't actually help that much that the person was you!" His voice is rising, and normally there'd be harmonics in it at that volume, but Gil sounds more worried than angry, Does the truth serum's euphoric effect block a Spark fugue? They'll have to try it out later.

Tarvek closes his eyes. "Technically you did," he points out.

"I'm trying very hard to believe that truth serum doesn't count. You could still run away. Why didn't you run away?" Well, he probably couldn't right _now_ because Gil is clinging to him like a tree octopus and Agatha has such a tight hold of his hand her nails must be close to drawing blood, oops, she really should let go, but it doesn't seem to bother Tarvek. Gil goes on, "You were right, though, offering to take it is very strong evidence that you're not about to betray us. It's just hard to trust you when you're so desperate to prove that I should."

Tarvek frowns. "Feedback loop," he says. "I was so desperate because you didn't."

"Exactly. So using the truth serum shorts out the loop -"

"- as long as it's both of us." Tarvek is beaming now, with the delight of having proved a theory. "Tell me you don't expect me to betray you?"

Gil points dramatically at a bit of decorative moulding on the opposite wall. "I am not having you watched. I am not checking your plans any more carefully than I check Agatha's. If you actually did betray us I wouldn't know what to do about it." He nods. "I know how not to let my own cognitive biases get in the way. It's not as if planning would help."

"Given that you're almost as much of a duplicitous weasel as me," Tarvek allows, "that's a touching declaration of faith."

Agatha is starting to feel warm and happy just watching them. She's so used to their perpetual sniping it turns into background noise and occasional hilarity, but looking at her boys snuggled up together with broad, if slightly loopy, smiles is the lifting of a weight she'd forgotten was there. Still, as the token sober person she ought to point a few things out. She gives Tarvek a reassuring pat on the hand and starts, "Is this going to last once the drugs wear off?"

Gil blinks a few times. "The faith? I don't know. Does it matter? We can work around it. I know he's not up to anything dangerous, I'll remember that however hard it is to feel it. And Tarvek got what he wanted."

"It's enough," Tarvek puts in. "I didn't _expect_ Gilgamesh to try taking the stuff himself, it seemed like too much to ask, but it worked out beautifully. This was a little manipulative," he adds, trying and failing to lift his head enough to look Gil in the face, "and I'm sorry. But I only just worked that out. It wasn't _calculated_. Are you going to be mad at me anyway when we're sober?"

Gil grimaces. "Probably, but I'll feel guilty about it."

It's a start, Agatha supposes. They have - about an hour, maybe less, to work it out before the artificial euphoria fades. If they want to try; they probably have quite enough to fret about already. Or avoid each other from sheer embarrassment about. Agatha certainly has enough to think over.

She could ask Gil if he's in love with Tarvek, but whether Gil has admitted as much to himself, in the privacy of his own head, she's not sure. And Tarvek would be hurt if he denied it, here and now. Does the truth serum drag things out of people they aren't ready to understand?

Well, it certainly makes thoughts flow more easily, and combined with how Gil wasn't showing the briefest glow of Spark, there's an obvious experiment. They have an hour. Probably less - they've fallen into a comfortable silence, and Agatha remembers an almost irresistible urge to babble. Maybe it's the dosage, or maybe they just need prompting. "That concrete recipe you mentioned in the Vatican library," she begins. "Gil, if you were planning an expedition to get it - I know it's reckless, but hypothetically - what would you need to have the best chance?"

"Map, to start with," he says automatically. "There's supposed to be a surviving catalog in Sicily, but who knows what the _Papa del Tutti_ wants for it?"

"Who cares?" Tarvek breaks in. "We have blackmail material on him."

"We do? Why am I not surprised?" Gil plants a kiss on the top of Tarvek's head. "Alright. We start by blackmailing the Pope, and once we have some idea where the target is, we work out the nearest roof with at least thirty square meters of open space directly underneath." Agatha's fingers itch to grab a pen and start sketching, she can already see ways the raid might go once it got through the roof, but her job isn't to _contribute_ , it's to _monitor cognitive function_. Gil goes on, "We get a coracle directly above it, then drop a Pascal's compass contractor."

"Use an elastic winch to make sure it doesn't spread," Tarvek adds. "If we're lucky, we didn't hit any canali, but if - ooooh."

They both have the look of a sudden bright idea. Agatha is fairly certain it's the same one she just had. Scientific objectivity, she reminds herself fiercely. _Check._ "Gil, what next?"

"Forced suction," he says. "A good high-powered pump -"

" - and we could clear out the entire canali system." Tarvek is beaming at nothing in particular again. "Disabling half its defenses at a stroke, at least until it built up sap again."

"Biological systems are easier to shock."

"How much sap does the Vatican hold, anyway?"

Everything Agatha knows about the Vatican library comes from a rather sensationalist book called _Terrifying Trees of the Continent_ she read when she was thirteen, so it's a little easier to sit back and listen to them ramble at each other, still without a trace of Spark. And watch them fiddle with each other's hair. That gives her ideas, but a very different set of ideas that she carefully puts aside for later. Tomorrow night, maybe.

\--

The serum had worn off too slowly for the memory to hit Tarvek like a sudden plunge into cold water. They'd been busy, going over the virtues of various plasma weapons as the spark crept back into their brains. Still, he isn't that surprised when Gilgamesh is waiting outside his bedroom door, or when he says, with the air of a man testing weight on a broken bone, "Since we were eight? Really?"

"Really and truly." Maybe it's just as well they went for the undignified way of getting the truth out of him. He would never have admitted that sober. 

"But ..."

"But what? Are you going to tell me children can't feel romantic love?"

Gilgamesh shakes his head. Opens his mouth. Closes it again. Lifts his hand, then brushes a bit of hair away behind his ear. "No," he says. "But I wanted to hear you say it again. You never have."

Would something flowery be appropriate? Declarations of his eternal devotion, preferably in rhymed couplets? But that's the sort of thing new lovers do, and he's been in love with Gilgamesh so long it's soaked into the secret corners of his soul, leaving nothing to splash over in rococco excesses of words. Besides, he's done enough soul-baring for the night. Good as it felt it left him exhausted.

"You first," Tarvek says.

Gilgamesh is still gaping as Tarvek closes the bedroom door behind him, and lets the smirk slip away from his face. 

\---

**Author's Note:**

> Thanks to PFDiva and aunt_zelda for looking this over. Eric Loder was shamelessly nicked from the Dorothy Sayers short story "The Abombinable History Of The Man With Copper Fingers".


End file.
